Carburetor



C. R.' SNYDER CARBURETOR Aug. 24, 1943.

" 2 sheets-sheet 2 Filed Dec. l0, 1940 i CHARpEs R. SNYDER,

-WdW/wza lower or inner end of the tube being threaded to receive aplug 1. This member has its upper end-'1A tapered as at 8 to guide airentering the cham-,-

ber through the tube 4 toward openings 9 formed in the side walls of thetube. Normally, vthese openings are closed by pivoted `gates I and soVheld by springs II. The resistance of the springs is of such an extentthat the shutters will be maintained in a closed position until thevolume of air passing into the mixing chambersr exceeds that capable ofpassing through a plurality of passages I2 extending through the plug 1.The outlet ends of the passages I2 terminate in restricted nozzles whichdischarge in the direction Aof impeller blades I3 formed on a plate I4constituting part of thefuel vaporizing mechanism.

By reason of the restrictions caused by the nozzles, the air enteringthe tube 4 will build up pressure suflicient to compress the springs Iland permit the shutters Ii) to open to admit air to the mixing chamber.The inclined surfaces at the inner end of the plug are provided withscoop-like baies I5 to insure a proper flow of air into the passages I2.As the air flows through the passages and the nozzles, it will impingethe impeller blades and cause the plate I4 to revolve about thelongitudinal axis of the mixingchamber. This rotation of the plate ismade possible through the provision of an antifriction bearing I5 towhich the plate I4 is secured. The stationary race of the'bearing issecured to a valve body I1 threaded into the open lower end of the plug1.

The plate i4 is providedwith depending pins I8, the lower ends of whichreceive and support a vaporizlng disk I9. This disk is disposed in ahorizontal plane and rotates with the plate I4 when air is` drawn intothe mixing chamber through the nozzles. The center of the disk I9 is inregistration withv the discharge end of the gas inlet passage whichextends axially through the member I1. A valve stem 20 is rotatablypositioned in this passage and has one side flattened as at 23a toregister with va reduced slot 2l extending laterally through the Vsideof the member I1 to provide for the flow of fuelV to the passage.

When the stem 20 is positioned as illustrated in Figs. 1 and 5, fuelcannot flow through the slot 2l. As the valve is rotated, however, theflat side will be presented to the slot and fuel will be permitted toflow into the passage from which it will be discharged onto the disk I9.Due to the rotation of the disk, this fuel will be discharged laterallyin the mixing chamber by centrifugal force, will vaporize and be mixedwith the air passing through the chamber. By controlling the rotation ofthe valve stem, the quantity of fuel permitted to pass through the lslot2l may also be controlled.

The fuel is conducted to the slot 2| through a tube 22, the inner end ofwhich is connected with a ring 23 between the bearing I5 and a shoulderon the body I1. `The ring23 has an annular recess formed therein toreceive the fuel introduced through thel tube V22. The outer end of thistube'communicates directly with thelfuel pump so that fuel will Vbedelivered to the carburetor Y `isjournalecl in the wall of the plug 1.The latter gear receives the splined end of a shaft 25,

the outer portion of which is journaled in a bearing provided in thecasing section 2. The extreme outer end of the shaft has a lever 26secured thereto, the movement of the lever serving to rotate the shaftwhich movement will be imparted by the gears to the valve stem. To movethe lever 26, it is connected by a link 21 with a second lever 23secured, as at 29, to a shaft 30, the intermediateportion 'of whichextends through theinlet tube 4. This shaft is flattened at its centralportion to receive the conventional throttle or butterfly valve 3|disposed in the inlet tube and employed to control flow of air into themixing chamber. The free end of the lever 28 has a perforated block 32pivotally secured thereto for the vslidable reception of one end of apusher rod 33. This member has an adjustable stop 34 lsecured theretoand a compression spring 35 surrounds-the rod'between the stop and theblock 32'. By this construction, the rodv 33 may be moved Aupward to`impart movement to the lever 28 in the operation of opening thethrottle.

If, for any reason, resistance to opening movement is imparted to thethrottle, the rod 33 may continue to move upwardly and compressthespring 35. Movement of thev throttle toward an open position may beresisted by the mechanism designated generally by the numeral 36 in Fig.1 of the drawings'. This mechanism is connected with the shaft 30 at theopposite side of the carburetor from the lever 28. The mechanism alsoincludes a lever 31, one end of which is secured tothe shaft 3D whilethe opposite end is pivotally connected with one end of a yoke-shapedlink 38. The lower or free end of the link supports a collar 39 slidablypositioned on the reduced extension of a piston rod 40.

When movement is imparted'to the lever 31, the link 38 will move thecollar upwardly against the lower end of a compression spring 4Idisposed between the collar and the inner upper end of a thirnble 42carried by the upper portion of the rod 40. This portion of the rod isthreaded as at 43 to receive an adjusting nut 44 through Y the movementof which theclearance between the lower end of the thimble. and thecollar may be varied. When the collar moves upwardly, the springwilltransmit this movement to the nut and, in turn,to the rod 4D..This-Inotionwill cause a piston 45 provided at the lower end of the rod40 to travel upwardly in an oil cylinder 46. This cylinder is rigidlysecured to the carburetor casing. 1 Y

As disclosed in Fig. 3, the piston has a plurality of ports extendingtherethrough which are normally closed by a spring-,pressed valve 41.When the piston moves upwardly, resistance will be/offered thereto bythe oil or other fluid contained within the cylinder and the vacuumpro-` l duced between the bottom of the piston and the cylinder. by-passline 48 is .connected with the ends of the cylinder so that as the.piston moves longitudinallythereof, the oil will flow thrcugh'the`by-pass to eliminate` the pressure appliedto `the top-of the `ipiston'and the vacuumapplied to the To permit the upward movement, ar

under side. When the piston moves-in `-a downward direction,-the-valve41'will be free to open and oil may flow throughthe'portsinithepiston without obstruction.

"I'o control the movement of the piston-inthe cylinder, the by-passlinehas a valve 49 positioned therein, this valve-being of the plug typeas disclosed in-Fig. 3, although otheretypes of valves may -be Yemployed with equal facility. When the valve is closed, the pistonwillbe restrained against upward'movement. Since the piston isconnectedwith theA link 38 through the spring and collar, resistance tomovement of the lever3'l will also bev offered'. This resistance willlie-transmitted through theshaft 30 to .the levers 28 and '26 so that`the throttle and-fuel lcontrol -valves will be `stopped in theirmovement toward-open positions. Normally, the valve 49 will be in anopen positionwwhen the engine with which the carburetor is connected isoperating under usual conditions. If the accelerator pedal should besuddenly depressed` or an unusual load applied tothe engine, the valve49 will be .closed to resist movement of the piston. lAt this time, thethrottle and fuel valves will Ibe stopped so that an excessive amountoffuel will not be introduced. After the engine has increased i-n speedor the load has been relieved, the valve will open and the throttle andfuel valves permitted to resume normal-operation.

The valve 49 is actuated by a lever Eiland a link which transmitsmovement from a vacuum `operated diaphragm52`to the'lever 59. Thediaphragm is carried by a housing 53 disposed in open communication withthe interior of the carburetor casing. A coil spring 54 is positioned inthe housing between the inner portion and the diaphragm. This springserves to move the diaphragm outwardly when the vacuum in the casing isreduced. When the spring moves the diaphragm,V the valve plug will berotated to close the by-pass line and the piston will be checked in itsupward movement. If pressureis applied to the accelerator at this time,the shaft'S may rotate and swing the arm 31 upwardly until the collar 39vengages the lower end of the thimble 42. Upward movement will then beprecluded until the diaphragm is drawn inwardly by vacuum'to restore thevalvev49 toits open position. The movement of the arm 3l between thestoppage of the piston and the engagement of thev collar 39 with thethi-mble permits the fuel con-V trol valve to move an additional amountwhereby the quantity of fuel introduced will be increased after theengine has slowed down because of an increased load.

By adjusting the nut 44, the increased amount of fuel may be varied toprevent the introduction of too much fuel which might stall the engine.Through the admission of this additional amount offuel, the speed of theengine will be increased and when the load is decreased to such anextent that the engine will operate normally, vacuum will be restoredand the valve returned to an open position. If the accelerator pedal isstill depressed when the valve opens, the energy stored in the spring 35will cause the lever 28 to move upwardly whereby the throttle and fuelvalves will be opened. After the lever 2 .8 has ceased to move, thespring 4| will con-` tinue to move the piston until vthe compression ofthe spring has been relieved. At this time, the collar 39 will beinengagement with a shoulder on the piston rod and when the pressure onthe throttle is released, the piston will be positively moveddownwardlyi 'The returnzof thelever 218 mitted bythe shafts25 and the`gearsd .tothe fuel valve to move it .to aclosed position.

The lever. 26 has an extension ,55. for thead.- justable reception of.astop screw 15.6. This Ascrew engage .an abutment .51. lto prevent-movement of the lever 2.6 to a position .wherein .valve f2ilwill becompletely closed. ,This provides sufcient Yfuel flow ,to permit themotor to operate atidling speed. The degree of opening maybe variedthrough the adjustment of stop screw 556,. A second projection .d8V isformed on .the lever 25 to limitthe `degree of opening vmovement of thefuel valve. This projection has an-adjustF able stop screw 5.9.

, Through the provision of` -thetcarburetorxabove described, thethrottle valve is located in .ad- Vance of the fuel vaporizing mechanismand is directly connected to the fuel control valve order than when thethrottle is opened, the fuel control valve will also be opelld'toincrease the flow of fuel. By introducingthe fuel tothe car.- buletorunder pressure. a ,quantity in p,rsmortioli to the needs of the motormay beprovided reeerdless of the speed .of operation. Through thelimiting device, this quantity ofrfuel may be .Con-

trollecl by e Condition of operation of the eneine so that in the eventa leed is applied to the engine to reduce its Speed. the amount-of fuelintroduced will not be sufficient to causethe engine to stall. I

When the throttle valve is positioned between the fu'el vaporizing meansandthe `engine as in conventional constructions, there is a tendency forthe fuel to condense through engagement with the throttle valve. Inaddition, there is grave danger of ice forming on the throttle due tothe lowered temperature ,resulting from rapid vaporization of the fuel.By positioning the throttle valve in advance ofthe fuel vaporizing meanswhichismadepossible by the construction set forth herein, the outletleading fromv the car.- buretor mixing chamber is unobstructed and maybe decreased in length to such anV extent that .the vaporizing meanswill be located immediately ad.- jacent to or infthe intakemanifold.When the outlet pSLSsage is thus decreased in length, the casing of thecarburetor may be heated to positively prevent any ice formation andprovide for a more rapid vapor-ization of fuel.

'To provide for relief forpressureswithin ,the

' mixing Chamber in the event-the engine equipped with the carburetorshould backfire, the top sectionA 2 has one or more openings 60 formedtherein. These openings are closed by pivoted covers 6l mounted on theouter sides of the section 2. Springs 62 engage the surfaces of thesection 2 and the coversV 6l to resiliently hold the latter in normallyclosed positions. -If the engine should backfire, the increasedpressure-within the carburetor `would have no deleterious effect becausethe covers 6| would-move open to vent the casing.

From the foregoing, it will be Seen that a carburetor has been providedwhereby the gas` to air ratio of the fuel mixture introduced totheengine Will be varied according to the ldemands for power made upon theengine.

What is `claimed is:

`1. In a carburetor of the type having a mixing chamber provided withinlet and outlet passages, fuel vaporizing means in said mixing chamberand means for conducting fuel under pressure to said vaporizing means, athrottle valve disposed in the inlet passage, resilient manually'operable means `for opening said throttle valve, valve means in saidfuel conductingmeans'for controlling the ow of fuel to said vaporizingmeans, motion transmitting means `connectingl said throttle and fuelvalves, means connected with one of said valves for interrupting themovement of said valve toward an open position,1 and means Iconnectedwith said "movement interrupting means and operative upon a decrease inthe .suction created by the engine equipped with the carburetor torender said movement interrupting means operative. l

2. In a carburetor of the type Vhaving a mixing chamber provided withinlet and outlet passages, fuel vaporizing means in said mixingv chamberand means for conducting. fuel under pressure to said vaporizing means,a throttle'valve disposed in the inlet; passage, resilient manuallyoperable means for opening said valve, valve means inV said fuelconducting means for controlling the flow of fuel to said vaporizingmeans, motion transmitting means connecting said throttle and vfuelvalves, means connected with one of said valves for interrupting themovement of said valve toward an open position, a lost motion connectionbetween said movement interrupting means and one of said valves andmeans connected with said movement interrupting means and operative upona decrease in the suction created by the engine equipped withthe'carburetor to render said movement interrupting means effective,said lost motion connection providing for a slight ad ditional movementof the valve connected therewith after said movement interrupting meansbecomes operative.

3. In a carburetor of the type having a mixing chamber provided withinlet and outlet passages, fuel vaporizing means in said mixing chamberand means for conducting fuel under pressure to said vaporizing means, athrottle valve disposed in the inlet, passage, resilient manuallyoperable means for opening said valve, valve means in said fuelconducting means for controlling the flow of fuel to said vaporizingmeans, means for simultaneously moving said valves toward openpositions, means rendered operative upon thedecrease of suction producedby the engine equipped with the carburetor to fix the extent of movementof said valves toward open positions, and means between saidlast-mentioned means and one of said valves to delay the effect of saidmeans on said valve.

4. In a carburetor of the type having a mixing chamber provided withinlet and outlet passages, fuel vaporiaing'means in said mixing chamberand means for conducting fuel under pressure to said vaporizing means, athrottle valve disposed in the inlet passage, valve means in said fuelconducting means for controlling the ow of fuel to said vaporizingmeans, means fory simultaneously moving said valves toward openpositions and means regulated by the suction of the engine forcontrolling certain operations of said valves, said means having acylinder for the reception of a quantity of fluid, a piston-movable insaid cylinder for displacing the fluid, means for connecting said pistonand said valves, the former being movable substantially in unson withthe latter, means establishing communication between the ends of saidcylinder onopposite sides of said piston, and means operative upon adecrease in suction produced by the engine equipped withthe carburetorto interrupt communication betweenjopposite ends .of said Ycylinder toprevent movementof said pistonand valves. Y y

5. In a carburetor of the type having a mixing chamberprovided withYinlet and outlet pas-` sages, fuel vaporizing means in saidmixingchamber and meansv for conducting fuel` under pressure to saidvaporizingmeanaja throttle valve dis,- posed in the inletpassage, valvevmeans -in said fuel conducting means for controlling the flowv of fuelto. said vaporizing means,`means for simultaneously moving said valvestoward open positions and means regulated by the suction of the enginefor controlling certain operations of said valves, said means having acylinderefor the reception of a quantity of fluid, a piston movable insaid cylinder for displacing the fluid,-alost motion yieldable couplingvconnecting saidpiston and said Valves, the former normally beingmovable in vunison with the latter, means establishing .communicationbetween the ends ofY said cylinder 'onopposite sides of saidvpiston,'and v means operative upon a decrease in suction produced bythe engine equipped with the carburetor to interrupt communicationbetween opposite ends of said cylinder to prevent movement vof saidpiston and valves, said lostmotion connection permitting the valves tomove a limited distance after the movement of theipiston is interrupted.

6. Ina carburetor, a casing formed Withan air passageway, the inlet ofsaid passagewaycommunicating with the atmosphere and the outlet with thecylinders of an associated engine, fuel vaporizing means disposedwithiny said passageway, a throttle valve arranged in said passagewayadjacent to the air inlet end thereof, resilient manually operable meansfor opening said throttle Valve, means for conducting fuel underpressure to said vaporizing means, valve Ymeans associated with saidfuel conductingfmeans forv controlling the flow of fuel to saidvaporizing means, motion-transmitting means directly connecting saidthrottle valve and fuel control valve means, and means controlledbyconditons of operation of the engine being served bythe carburetor forautomatically limiting the extent of movement of said hrottle valve andfuel control valve means toward open fluid-flow admitting positions. f f

7. In a carburetor, a-casingy formed with an air passageway, the inletofsaid passageway communicating with the atmosphere and the outlet withthe cylinders `of an associated engine, Yfuel vaporizing means disposedwithin said passage- Way, a throttle valve arranged in said passagewayadjacent to the air inlet end thereof, resilient manually operable meansforopening saidV throttle valve, means for conducting fuel underpressure to said vaporizing means, valve means associated with said`fuel conducting kmeans for controlling theflow of fuel to saidvaporizing means, motion-.transmitting means directly connecting saidthrottle valve and fuelcontrol valve means, d means connected with, saidthrottle and fuel control valve means for automatically limiting theextent of movement thereof toward openfluid-,flow admitting positions,said limiting means having a variable stop, and means actuated by vacuumproduced in the engine served'r CHARLES asNYDER,

